1. Field of the Invention
This invention relates to a photographic printing apparatus provided with a make-over printing function. This invention particularly relates to a photographic printing apparatus for color photographs provided with a make-over printing function.
2. Description of the Prior Art
As color photographic printing systems, there have heretofore been known a simultaneous printing system and an extra printing system. In the simultaneous printing system, after development of exposed negative films, all originals recorded in the negative films are printed in photographic paper. On the other hand, in the extra printing system, among the originals developed in the negative films, only those specified by customers are printed in a desired number of photographic paper sheets.
In the simultaneous printing system, many developed negative films are connected with each other to a continuous length, and marks corresponding to information comprehended in the originals in respective negative films are put in the respective negative films. Then, printing is conducted quickly and continuously in a manner suitable for the originals developed in the negative films. For example, the aforesaid continuous length is constituted by 12-frame or 24-frame rolls of films in a number within the range of about 100 pieces to about 200 pieces.
When the simultaneous printing process is conducted, the printing apparatus measures densities of three primary colors (red, green, and blue) included in the originals recorded in the negative films. Then the printing apparatus conducts calculations using information on correction according to the picture patterns of the color negatives and printing conditions in the printing apparatus, and determines exposure amounts of the photographic paper sheets with respect to cyan, magenta and yellow. Thus color ratios are corrected to obtain a desired color tone, and the originals are printed in photographic paper sheets.
However, in the aforesaid simultaneous printing process, defective prints exhibiting color tones different from those desired by the customers arise in a ratio generally within the range of several percent or less. Such defective prints are subjected to a make-over process which is called a remake printing and which is carried out on the basis of printing information recorded, for example, on the back side of each print at the time of simultaneous printing.
On the other hand, in the aforesaid extra printing system, most customers desire to obtain extra prints exhibiting approximately the same tones as those of prints previously produced by simultaneous printing and given by the customers to an extra printing operator. Thus the extra printing operator uses the prints given by the customers as sample prints, and visually recognizes the printing conditions recorded, for example, on the back sides of the sample prints. On the basis of the printing conditions thus recognized, the extra printing operator conducts printing.
As described above, in the conventional techniques, it is necessary for printing operators to visually recognize the printing information recorded, for example, on the back sides of defective prints arising during the simultaneous printing and the sample prints given by customers for extra printing, and to produce acceptable prints on the basis of the printing information thus recognized. Thus recognition of deviations from printing conditions for the three primary colors, i.e. red, green and blue, must depend on intuition of the printing operator. Therefore, printing accuracy and efficiency become very low.
Further, in the conventional make-over printing process, the first print and the second print are generally produced by use of different printers. When there is a difference in the printing setting conditions between the different printers, the difference in the printing setting conditions between the printers must also be taken into consideration when the make-over printing operator determines the correction amount of the exposure conditions. Thus the printing work becomes complicated, and there is the risk of a mistake arising in the printing work.